Integrated circuits are manufactured by building semiconductor devices on one or more substrates in a process chamber. The semiconductor devices are interconnected to form the integrated circuit (IC). A semiconductor wafer may have one, or many, or a few ICs.
Semiconductor devices are fabricated on substrates such as silicon wafers by processes that involve depositing, patterning, and removing of materials on the substrates.
Deposition processes such as chemical vapor deposition (CVD) or physical vapor deposition (PVD) may be used to deposit a layer of material on a substrate.
Photolithography techniques may be used to create a pattern on a layer of material to control where etching, depositing, or implanting will occur.
Etch processes may be used to remove portions of a deposited layer, so that other materials may be deposited in the removed portions.
Ion implantation processes may be used to change the properties of a deposited layer of material by physically bombarding and implanting dopants into the deposited layer.
By using various ones of these process steps, semiconductor devices, and, thus, integrated circuits are created on the substrate.
In fabricating ICs, specialized process chambers are used sequentially to perform the steps required to build the semiconductor devices and the ICs. For a complex integrated circuit, hundreds of individual process steps may be involved in building and interconnecting all of the underlying semiconductor devices.
To streamline the manufacturing process, process chambers may be integrated into a cluster tool, so that the different process steps may be executed sequentially and efficiently, using less factory space than stand-alone chambers, and requiring less distance to transport wafers from process step to process step.
A cluster tool provides process sequence integration by “clustering” several different process chambers into one platform.
By using a cluster tool different processes can take place in sequence on the same platform without the need to break pressure seals in the process environment. As a result, there may be fewer opportunities for unwanted contamination to occur.
In addition, it is possible to save some or all of the time involved in completely venting up a chamber, moving a substrate from stand-alone chamber to stand-alone chamber, and then pumping down each succeeding chamber to achieve the necessary level of vacuum to conduct the next process sequence.
Because of the complexity of the manufacturing process, there is frequent inspection of substrates to ensure that the process steps are executed properly and that the substrates are reasonably free of defects, preferably as free of defects as is practicable.
Process chambers are usually designed and built to meet dimensional footprint requirements of the manufacturing floor on which the semiconductor fabrication tools are located. However, there are no similar requirements for inspection systems, and conventional measurement/inspection systems, typically, can be relatively bulky, and can have relatively large footprints.
Therefore, inspection systems usually are not integrated into cluster tools, but instead are separate from cluster tools. Accordingly, an evaluation chamber that can be integrated into a cluster tool would further streamline the manufacturing process for integrated circuits.
There is a need to allow efficient and relatively a small footprint, compact measurement/inspection system that is connected or integrated with a process tool, or a process control tool to enable a better control loop by processing and receiving immediate high resolution imaging data. Such apparatus is also contamination free system for moving a substrate.